There is lots of discussion about this on the board and there can be various reasons depending on your setup. The most likely reasons are (sorry no a lot of detail I'm away from my edison right now) :
- if you have an arduino setup you may have the usb host/device switch in the wrong position
- if you have a mini breakout board it is probably the way you supply power. You need to either supply power via the 2 pin .1"c-c power connector (not battery connector)or solder a barrel (power supply) connector on the back and supply power via that
Otherwise search the forum... there have been lots of threads about this.
Thank you for your replay. My usb has no power, so I get that problem.